Monitoring the amount of fuel in a fuel tank is critical for vehicle operation because there are many functions within an engine that rely on fuel tank level information. The fuel level is normally monitored by a fuel tank level sensor that outputs a value corresponding to the current fuel level. As fuel is consumed, the value output by the sensor goes down. If the fuel tank level sensor sticks or otherwise malfunctions, however, it cannot output a signal that accurately reflects the fuel level in the tank. An incorrect fuel tank level sensor value may adversely affect other engine functions. The operation of the fuel tank level sensor is controlled by an algorithm.
Currently known algorithms are designed to diagnose electrical errors detected by the sensor (e.g., a short-to-battery error, short-to-ground error, or open circuit) or a stuck sensor. However, these algorithms can identify only a limited range of possible sensor malfunctions, leaving other sensor malfunctions undetectable.
There is a desire for a system that can detect a fuel tank level sensor error more reliably.